Actinomycetes, most notably the genus Streptomyces, have great importance due to their role in the discovery of new natural products, especially for finding antimicrobial secondary metabolites that are useful in the medicinal science and biotechnology industries. In the current study, a genome-based evaluation of Streptomyces sp. isolate BR123 was analyzed to determine its biosynthetic potential, based on its in vitro antimicrobial activity against a broad range of microbial pathogens, including gram-positive and gram-negative bacteria and fungi. A draft genome sequence of 8.15 Mb of Streptomyces sp. isolate BR123 was attained, containing a GC content of 72.63% and 8103 protein coding genes. Many antimicrobial, antiparasitic, and anticancerous compounds were detected by the presence of multiple biosynthetic gene clusters, which was predicted by in silico analysis. A novel metabolite with a molecular mass of 1271.7773 in positive ion mode was detected through a high-performance liquid chromatography linked with mass spectrometry (HPLC-MS) analysis. In addition, another compound, meridamycin, was also identified through a HPLC-MS analysis. The current study reveals the biosynthetic potential of Streptomyces sp. isolate BR123, with respect to the synthesis of bioactive secondary metabolites through genomic and spectrometric analysis. Moreover, the comparative genome study compared the isolate BR123 with other Streptomyces strains, which may expand the knowledge concerning the mechanism involved in novel antimicrobial metabolite synthesis.

The major challenge in large‐scale industrial use of lipopeptide surfactin is the low yield by indigenous bacterial strains and the higher cost of its production that have been proved as a limiting factor in commercial applications. Therefore, there is an urgent demand for high‐yielding strains that can be achieved through strain improvement. A first report on the use of a combination of UV and gamma‐irradiation mutagenesis for the development of surfactin hyperproducing mutants of Bacillus spp. proved to be significant and resulted in a twofold enhancement in surfactin yield. The mutant was able to grow and produce surfactin on all the tested carbon and nitrogen sources, while 2% glycerol favored maximum surfactin yield (1.62 g/L) as compared to the wild‐type strain that showed a maximum 0.85 g/L surfactin yield at 3% sucrose. Additionally, the mutant exhibited a good yield of pure surfactin, that is, 1.55 g/L as compared to the wild strain (0.411 g/L) by using corn steep liquor as the main component of the fermentation medium. The study concluded overall a threefold enhancement in the relative abundance of purified surfactin and its isoforms detected by matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) analysis in mutant strain AF‐UV γ 2500.

Nanobiotechnology has gained significant attention due to its capacity to generate substantial benefits through the integration of microbial biotechnology and nanotechnology. Among microbial organisms, Actinomycetes, particularly the prominent genus Streptomycetes, have garnered attention for their prolific production of antibiotics. Streptomycetes have emerged as pivotal contributors to the discovery of a substantial number of antibiotics and play a dominant role in combating infectious diseases on a global scale. Despite the noteworthy progress achieved through the development and utilization of antibiotics to combat infectious pathogens, the prevalence of infectious diseases remains a prominent cause of mortality worldwide, particularly among the elderly and children. The emergence of antibiotic resistance among pathogens has diminished the efficacy of antibiotics in recent decades. Nevertheless, Streptomycetes continue to demonstrate their potential by producing bioactive metabolites for the synthesis of nanoparticles. Streptomycetes are instrumental in producing nanoparticles with diverse bioactive characteristics, including antiviral, antibacterial, antifungal, antioxidant, and antitumor properties. Biologically synthesized nanoparticles have exhibited a meaningful reduction in the impact of antibiotic resistance, providing resources for the development of new and effective drugs. This review succinctly outlines the significant applications of Streptomycetes as a crucial element in nanoparticle synthesis, showcasing their potential for diverse and enhanced beneficial applications.

We present the genome sequence of Streptomyces sp. strain R1, isolated from water canal sediments and possessing genes responsible for antimicrobial metabolites and plant growth promotion. The genome assembly contains 7,936,694 bp with 72.24% of guanine-cytosine content. This genome will provide basic knowledge of the genes and pathways involved in the above mechanisms.

The present study reports the isolation and molecular identification of Streptomyces sp. strain WSN‐2 using 16S rRNA gene sequencing and BLASTn analysis (GenBank Accession No. MN128377), followed by its application in the green synthesis of silver nanoparticles (AgNPs). Biomass filtrate of Streptomyces sp. WSN‐2 efficiently reduced silver ions to form stable AgNPs, confirmed by a characteristic UV‐Vis surface plasmon resonance (SPR) peak at 423 nm. Structural and morphological characterization using FTIR, SEM, TEM, and EDX revealed spherical nanoparticles with a smooth texture and well‐dispersed arrangement. TEM analysis indicated particle size predominantly between 50 and 60 nm (overall range 0.83–100 nm), while the zeta potential of –22.9 mV confirmed moderate colloidal stability. EDX spectra displayed strong elemental silver absorption peaks at 3‐4 keV, indicating crystalline Ag formation. The biosynthesized AgNPs exhibited strong antimicrobial activity against wide range of pathogenic microbes. Maximum antibacterial growth inhibition zones were observed against S. typhi (24 ± 1.53 mm), followed by E. coli (23 ± 1.25 mm), B. subtilis (23 ± 1.73 mm), and P. aeruginosa (22 ± 1.53 mm). Antifungal assays revealed highest antifungal activity against A. flavus (16 ± 1.15 mm), and notable inhibition of A. niger (16 ± 1.25 mm), A. fumigatus (15 ± 1.70 mm), and F. oxysporum (14 ± 1.53 mm). MIC values ranged from 8.00 ± 0.05 µg/mL for P. aeruginosa to 18.000.07 µg/mL for A. fumigatus . The AgNPs also demonstrated remarkable antioxidant potential, achieving 65.2% H₂O₂ scavenging activity at 50 µg/mL, surpassing L‐ascorbic acid (45.1%). These findings highlight Streptomyces sp. WSN‐2 as a promising biogenic source for the synthesis of stable AgNPs with significant antibacterial, antifungal, and antioxidant potential.

Biosurfactants are increasingly recognized for their versatile applications across industries, including bioremediation and pharmaceuticals. Among these, lipopeptides, produced notably by Bacillus species, demonstrate promising surface activity and biocompatibility. This study investigates the toxicity of lipopeptides biosurfactants derived from the AF_3B strain of Bacillus velezensis. The research delves into the production of lipopeptides biosurfactants from AF_3B and their characterization through antibacterial bioassays, revealing a significant inhibition of various bacterial strains. In vitro assays demonstrate the ability of lipopeptides biosurfactants to suppress the growth of key mycotoxigenic fungi (Aspergillus niger and Fusarium oxysporum) maximum to 86%, confirming their potential as a biological control. In ovo toxicity is assessed by injecting fertile chicken embryos with varying doses (30, 15, 7.5, 3.75, and 1.87 mg/mL) of lipopeptides biosurfactants obtained from AF_3B. The embryos exhibit normal development and high survival rates, indicating negligible toxicity. Overall, this study highlights B. velezensis strain AF_3B as a valuable candidate against bacterial and fungal diseases and foodborne pathogens, and in healthcare sector, underscoring the potential of lipopeptides biosurfactants in diverse industrial applications.